KR102111132B1 - How to control the clutch release of the sliding gear - Google Patents

Abstract

A method for controlling the clutch release of the sliding gear (1) of the gearbox with dogs (1a) forced to rotate with the shaft of the vehicle gearbox, the sliding gear on the gearbox, at least two At least one engaged position and a neutral clutch on the hybrid gear in which the sliding gear is engaged on a pinion rigidly coupled to the shaft to transfer torque received from separate power sources to the wheels of the vehicle incrementally or otherwise. It can move axially under the control of a powered shift actuator between released positions, the method comprising:
-Applying a zero torque request to all power sources of the vehicle,
-Applying a clutch release instruction to the sliding gear,
-If there is no rapid clutch release, estimating the resistive torque (C _r ) on the dogs 1a of the sliding gear,
-Calculating the residual torque (C _res ) on the dogs as a function of the calculated resistive torque and the angle of departure from the calculated resistive torque,
_-Erasing the residual torque (C _res ) by applying opposing torques (C1, C2) on the sliding gear,
-It comprises a step of releasing the clutch.

Description

How to control the clutch release of the sliding gear

The present invention enables different transmission ratios between at least two power sources (thermal and electrical) of the vehicle and their drive wheels, without any integrated mechanical synchronization system or input clutch, and gear shift ( It relates to hybrid power trains that include a dog gearbox that does not have any torque interference between the combustion engine and the gearbox during the shift).

More particularly, the present invention relates to a method for controlling declutching of a sliding gear of a vehicle dog gearbox, the sliding gear being forced to rotate with the shaft of the gearbox, the gear The sliding gear on the box is on a pinion rigidly connected to the shaft to transmit torque received from at least two separate power sources to the wheels of the vehicle incrementally or otherwise. The sliding gear can move axially under the control of a powered shift actuator between at least one engaged position on the hybrid gear engaged and a neutral clutched released position.

The present invention is to and from internal combustion of at least one electric machine capable of simultaneously transmitting torque to the wheels of a vehicle across at least one hybrid gear that is engaged and disengaged, respectively, by engaging and disengaging a sliding dog gear on a pinion gear. It also relates to a hybrid power train comprising a multi-stage gearbox linked on the primary line without any shorting clutch to the engine.

When the hybrid power train includes sliding dog gears without any input clutch that prevents torque transmission between the internal combustion engine and the wheels during gear shift without an integrated synchronization system, the sliding gear dogs Synchronization of the pinion prior to engagement with the pinion's dogs on its shaft is usually done by controlling the electric motor and / or the internal combustion engine.

To ensure that the engaged gear ratio is maintained, special trapezoidal-shaped teeth known as “dogs” can be used, as shown in FIGS. 1 and 2. In Fig. 1, the sliding gear is in a neutral state and at the same distance g from two pinions (not shown). The dogs 1a of the sliding gear 1 and the dogs 2a of the pinner (not shown) are cut into a trapezoidal shape, so that the gears are mutually engaged in a gear ratio position where the torque transmission in the gears is engaged. Try to maintain or improve. This is the "anti-disengagement" function. The inclination of the dogs produces an inclined reaction force F _R with respect to the traction force F _T applied to the dogs by the torque of the drive shaft. The reaction force F _R is the opposite of the arbitrary output force F _S from the dogs of the sliding gear.

Under these conditions, the torque transmitted by the shaft must be canceled to allow the sliding gear to be disengaged. If the gearbox has an input clutch (or short-circuit clutch), this problem is solved simply by opening the clutch during operation. In the absence of any shorting clutch, a disengagement actuator is needed that is sufficiently powerful to overcome the frictional forces produced by the escape prevention function.

All driving power sources of the power train, for example an internal combustion engine and one or two electric machines, can generate residual torque on the hybrid gears. These are controlled in such a way as to attempt to clear residual torque on the shaft during clutch release. The ideal solution to ensure the deviation of the sliding gear is to cancel the requested torque of the three motors. Electric motors provide good response time. Their torque can be canceled in less than 100 ms. Conversely, internal combustion engines can have a response time of over 500 ms at certain points of operation, especially at low speeds. Erasing the torque on the sliding gear can take more than 1 second. This time is unacceptable in terms of driving comfort, as torque cancellation time is an integral part of gear shift time.

The first approach to immediately erasing torque from the internal combustion engine utilizes estimating the torque from the internal combustion engine processor on the vehicle's communication network, and involves attempting to absorb this torque during the temporary erasure process. do. The success of this method relies on other motors (electric machines) that have the ability to absorb this temporary torque. In the best case scenario, the motors need to accurately absorb the reverse of the torque supplied by the internal combustion engine. Indeed, the torque of the sliding gear is reduced, but the torque estimation of the internal combustion engine is not sufficiently precise for offsetting by other motors to enable clutch release in all cases.

3 shows a failed clutch release sequence by offsetting the thermal torque by the electric machines. This failure was caused by a static error on the estimated torque Ce of the internal combustion engine. If the initial torque injection cutoff is 0 Nm, the actual torque C _R of the internal combustion engine is negative. The set point torque C _c of the electric machine is zero. If the zero torque of the electric machine is requested at time d, the clutch release fails due to the escape prevention devices. Indeed, the actual torque C _R in the sliding gear is maintained above the clutch release threshold S (in absolute terms).

The activation time of the shift actuator also limits the chances of success of the action, since these actuators cannot be stressed too long before overheating. If the residual force on the dogs of the sliding gear is still high when the actuator is stopped, the clutch release fails. In the common case where the actuator operates on a sliding gear by means of a selector fork, it is possible that it may not move sufficiently to disengage the gear ratio.

The inaccurate estimation of the torque dynamics of the internal combustion engine may also be the cause of its own failure. The common case shown in FIG. 4 is that the estimated torque Ce quickly converges towards its zero target, while the actual torque C _R provided by the motor drops more slowly, which is usually more than 1 second to be erased. This is because it requires a lot. The set point torque C _c of the electric machine is erased too quickly. The attempt to release the clutch is too early because the actual torque C _r of the internal combustion engine is still high. In FIG. 4, if the time (d1 to d2) when the clutch release request is outside the clutch release threshold S is too long, the clutch release request is impossible because the time is greater than the maximum active time Tmax of the actuator.

The present invention is intended to ensure clutch disengagement of a sliding gear using a new method based on correct estimation of residual torque on a sliding gear that is not sensitive to inaccuracies in torque estimates of an internal combustion engine.

The proposed method includes the following steps:

-Applying a zero torque request to all power sources of the vehicle,

-Applying a clutch release instruction to the sliding gear,

-If there is no rapid clutch release, estimating the resistive torque on the dogs of the sliding gear,

-Calculating the residual torque on the dogs as a function of the calculated resistive torque and the anti-disengagement angle of the calculated resistive torque,

-Applying the opposite torque on the sliding gear to erase the residual torque,

-Clutch release step.

The method is particularly safe and is compatible with the thermal forces of the gear seat actuation module.

The effects of the present invention are specified individually in the corresponding parts of the specification.

The invention is further described in the description below of the non-limiting embodiments provided with reference to the accompanying drawings.
1 is a schematic representation of a sliding gear in neutral between two pinions.
Figure 2 shows the forces present during disengagement.
3 and 4 show two cases where clutch release is not possible on a hybrid power train without an integrated synchronization system or input clutch.
5 is a resistive torque observer on a dog.
6 is a map of resistive torque as a function of residual torque.
7 is a diagram of an implementation strategy.

The first part of the method involves estimating the residual torque C _res on the dog. The estimation itself is actually related to the resistance torque C _r on the dog. The resistive torque C _r can be estimated by an observer as in FIG. 5 using the following data:

* X _f : Position measurement of the selection fork (not shown) of the sliding gear

* F _ressort : Force applied by auxiliary spring

* K _ressort : torque coefficient of auxiliary spring, and

* I _f : Fork inertia.

The inertia I _f is a function of the distance between the position of the control member of the sliding gear, such as a selection fork, and the position of the actuating finger of the sliding gear. The force applied by the auxiliary spring depends only on the fork position. The equation controlling the movement of the fork is as follows:

This makes it possible to calculate the gain on the inertia of the fork, which is compared to the force of the spring to obtain the resistive force. The resistive torque C _r is obtained by subtracting the force F _ressort of the spring from the gain on the inertia I _f of the fork calculated as a function of the acceleration of the resistive torque. This provides an estimate of the resistive torque on the dogs. The residual torque also depends on the angle of departure from the residual torque. For a given anti-deviation angle α, the resistive torque on the dogs can be mapped as a function of the residual torque C _res as shown in FIG. 6, where two straight lines depend on the anti-deviation angle α, the same resistance Convert torque C _r to two opposite residual torque values C _res in the dog. Applying one of the values to the dogs of the sliding gear cancels the residual torque C _res , while the other of the values doubles the residual torque.

The solution employed is to request the electric motor to apply a randomly selected torque between the calculated two residual torque values C _res . If the applied value actually erases the torque of the internal combustion engine, the fork moves toward the neutral position, and clutch release is performed. If it is identified that the fork moves from its neutral position, the torque of the electric machine increases the residual torque. Thereafter, a second value is applied to necessarily erase the residual torque. Clutch release is performed.

The strategy is summarized in FIG. 7 (a non-limiting example of a power train comprising an internal combustion engine and a single electric machine). More generally, the present invention applies to controlling the release of the clutch of the sliding gear of any vehicle dog gearbox, the sliding gear being forced to rotate with the shaft of the gearbox, the sliding gear on the gearbox Is, at least one on the hybrid gear in which the sliding gear engages on a pinion rigidly connected to the shaft to transmit torque received from at least two separate power sources to the wheels of the vehicle incrementally or non-incrementally. Between the engaged position and the neutral clutched position, it can move axially under the control of a powered shift actuator.

When the gearbox is commanded to perform a gear shift that includes clutching the sliding gearbox, a zero torque request is applied to the internal combustion engine Mth and to the electric machine ME. When the torque values are estimated to be low enough to enable disengagement, the disengagement instruction is sent to the shift actuator discussed. If disengaging does not occur within a given time, such as 50 ms, it is assumed that there is still excess residual torque on the dog. The hypotonic torque C _r is then estimated, and can be used to calculate the erase torque values C1 and C2 for the residual torque C _res . The first is applied, for example, for 50 ms, to check the gradual change of the fork position. The direction of movement of the selection fork of the sliding gear is identified during the application of the first erase torque value C1. Following the application of the first value C1, if the fork moves out of the neutral position, a second value C2 is applied for the same time as the first value, to ensure clutch release. The two opposing erase torque values C1, C2 are continuously applied to the sliding gear if one of the erase torque values fails. With the indicated times, the clutch release is achieved in all cases in less than 150 ms.

In summary, the method includes at least the following steps:

-Applying a zero torque request to all power sources of the vehicle,

-Applying a clutch release instruction to the sliding gear,

-Without rapid clutch release (t> 50 ms), estimating the resistive torque C _r on the dogs of the sliding gear,

-Calculating the residual torque C _res on the dogs as a function of the calculated resistive torque and the angle of departure from the calculated resistive torque,

-Erasing the residual torque C _res by applying opposing torques C1 and C2 on the sliding gear,

-Clutch release step.

The main advantage of the present invention is that there is no need to add anything to existing gear shift actuation modules. The present invention also eliminates the need to size the actuation motors.

If the gear shift has to be taken in about 1 second, the increased clutch release time generated by the implementation of the present invention, for example, 50 ms to 150 ms, is an acceptable limit in terms of driving comfort. Within.

The above description presents one preferred method for estimating resistive torque. However, other observation techniques that are equally robust against measurement noise can be employed as a function of the quality of available fork position measurements without departing from the scope of the present invention.

As a variant, a torque scan can be performed by the electric machine without previously estimating the resistive torque. However, this deformation greatly increases the clutch release time, because instead of choosing between two torque values, it is selected from a wide range of values, and the scan takes a long time to complete. The method nevertheless makes it possible to ensure clutch release in all cases without sizing any component of the actuator.

As indicated above, the proposed method is capable of simultaneously transmitting torque from the gearbox to the wheels of the vehicle over at least one hybrid gear that is engaged and disengaged, respectively, by engagement and disengagement of the sliding dog gear on the pinion gear. Advantageous to any hybrid power train that includes a multi-step gearbox linked to a primary line without any shorting clutch to the internal combustion engine and to at least one electric machine. Is applied.

In such a power train, disengaging the sliding gear can be controlled by applying the above method. The method is particularly effective when the sliding gears under discussion do not have integrated synchronization systems and when the dogs of the sliding gears have a non-zero departure angle.

Claims (10)

As a method for controlling the release of the clutch of the sliding gear (1) of the gear box equipped with dogs (dog) (1a) forced to rotate with the shaft of the vehicle gearbox,
The sliding gear on the gearbox is a pinion rigidly connected to the shaft to transmit torque received from at least two separate power sources to the wheels of the vehicle incrementally or non-incrementally. ), Between the at least one engaged position on the hybrid gear on which the sliding gear is engaged and the neutral disengaged position, can move axially under the control of a powered shift actuator, the method comprising:
-Applying a zero torque request to all power sources of the vehicle,
-Applying a clutch release instruction to the sliding gear,
-If there is no rapid clutch release, estimating the resistive torque (C _r ) on the dogs 1a of the sliding gear,
-Calculating the residual torque C _res on the dogs as a function of the calculated resistive torque and the anti-disengagement angle of the calculated resistive torque,
_-Erasing the residual torque (C _res ) by applying opposing torques (C1, C2) on the sliding gear,
-Control method comprising the step of releasing the clutch. According to claim 1,
_{Characterized} in that two opposite erase torque values (C1, C2) for the residual torque values (C _res ) are calculated and continuously applied to the sliding gear if any one of the erase torque values (C1, C2) fails. Control method. According to claim 2,
The control method characterized in that the movement direction of the selection fork of the sliding gear 1 is identified during the application of the first erase torque value C1. According to claim 3,
When the fork deviates from its neutral position following application of the first value, the second erase torque value (C2) is applied to the sliding gear. The method of claim 3 or 4,
The resistive torque (C _r ) on the sliding gear is:
-A measurement of the position of the fork of the sliding gear (X _f )
-Force applied by the auxiliary spring,
-The torque coefficient of the auxiliary spring (K _ressort ), and
-The inertia of the fork (I _f )
Control method characterized in that it is estimated as a function of. The method of claim 5,
The resistive torque (C _r ) is obtained as a function of its acceleration by subtracting the force (F _ressort ) of the spring from the gain on the inertia (I _f ) of the fork. The method according to any one of claims 1 to 4,
Wherein the power sources include at least one internal combustion engine and one electric machine. The method of claim 7,
The residual torque (C _res ) is applied to the sliding gear by the internal combustion engine, wherein the erasing torques (C1, C2) for the residual torques are applied by the electric machine. Any to and from the internal combustion engine and to at least one electric machine capable of simultaneously transmitting torque to the wheels of the vehicle across at least one hybrid gear that is engaged and disengaged, respectively, by engaging and disengaging the sliding dog gear on the pinion gear. A hybrid power train comprising a multi-stage gearbox linked on the primary line without a short circuit clutch,
Releasing the clutch of the sliding gear is a power train, characterized in that controlled as claimed in any one of claims 1 to 4. The method of claim 9,
The sliding gear does not have any integrated synchronization system, and the dogs of the sliding gear have a different anti-disengagement angle than the power train.

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